How long to image the Hercules Cluster with the Unistellar eQuinox 2
From a Bortle 6 suburban sky, the Unistellar eQuinox 2 needs about 6 min (94 subs of 4 s) for a solid image of the Hercules Cluster. A quick look takes 2 min; a showpiece 25 min. Under a Bortle 3 rural sky the solid figure drops to 4 min. At Bortle 6 the limit is a mix of skyglow and read noise. In this scope's field it fills 58% of the frame’s short side.
| Sky | Quick lookTarget obvious, still noisy | SolidClean enough to share | ShowpieceSmooth faint detail, print-worthy |
|---|---|---|---|
| Bortle 1Excellent dark site | < 1 min15 subs | 4 min57 subs | 15 min227 subs |
| Bortle 2Typical dark site | < 1 min15 subs | 4 min58 subs | 15 min232 subs |
| Bortle 3Rural | < 1 min15 subs | 4 min60 subs | 16 min240 subs |
| Bortle 4Rural / suburban transition | 1 min17 subs | 4 min66 subs | 17 min261 subs |
| Bortle 5Suburban | 1 min19 subs | 5 min74 subs | 20 min294 subs |
| Bortle 6Bright suburban | 2 min24 subs | 6 min94 subs | 25 min374 subs |
| Bortle 7Suburban / urban transition | 2 min33 subs | 9 min132 subs | 35 min527 subs |
| Bortle 8City | 3 min48 subs | 13 min192 subs | 51 min765 subs |
| Bortle 9Inner city | 5 min80 subs | 21 min318 subs | 1 h 25 min1,272 subs |
Power and kit for this session
Allowing for slewing, focusing and rejected subs, that is about 8 min of run time. The eQuinox 2’s battery (rated about 11 h) should cover it; a power bank still keeps the phone running the app alive. (Bortle 6, solid image; we allow 30% over the integration time.)
- USB-C power bank 20000mAh 5V 2AUnistellar asks for a 5 V 2 A output; PD is not needed.
- red LED head torchRed light keeps your night vision; white light costs you twenty minutes of dark adaptation every time.
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Everything that fits the eQuinox 2 →
How it frames
The Hercules Cluster is 20′ across. The eQuinox 2 frames 0.76° × 0.57° at 1.33″ per pixel, so it fills 58% of the frame’s short side.
About the Hercules Cluster
The great northern globular, a few hundred thousand stars in a ball a third the Moon's width. Quick and always satisfying.
M13, NGC 6205 · Globular cluster in Hercules · magnitude 5.8 · 20′ · best in May, Jun, Jul. Reachable from mid-northern latitudes (UK, northern US, central Europe) and from the south.
Globular clusters are point sources packed tight, so they come quickly: the core resolves into stars within a handful of minutes on any smart scope. More time deepens the halo and pulls in the faint outer members. Use short subs so the core does not saturate into a white blob, and no filter.
About the Unistellar eQuinox 2
A 114 mm Newtonian with five times the light grasp of a 50 mm refractor. Fixed 4 s subs put it in read-noise territory under dark skies, but the aperture carries it. The published field is 45.6′ × 34.2′, a crop of the sensor.
Fixed 4 s subs in Enhanced Vision; they cannot be changed. No built-in filter. Unistellar sells only a solar filter and says a third-party filter is at your own risk and voids the warranty.
The eQuinox 2 uses fixed 4 s subs, so the only levers you have are the sky you shoot from, the filter, and total time.
Stack across nights. Every smart scope app can continue a stack or you can combine the saved frames on a computer; the figures here are totals, not single-session limits.
Have an image of the Hercules Cluster from a eQuinox 2? Email it with your total time and sky to [email protected] and it goes here, credited.
Same target, other telescopes
- Hercules Cluster with the ZWO Seestar S50: 7 min from Bortle 6
- Hercules Cluster with the ZWO Seestar S50 Pro: 8 min from Bortle 6
- Hercules Cluster with the ZWO Seestar S30: 8 min from Bortle 6
- Hercules Cluster with the ZWO Seestar S30 Pro: 8 min from Bortle 6
- Hercules Cluster with the DwarfLab DWARF 3: 11 min from Bortle 6
- Hercules Cluster with the DwarfLab DWARF mini: 8 min from Bortle 6
- Hercules Cluster with the DwarfLab Draco: 15 min from Bortle 6
- Hercules Cluster with the DwarfLab DWARF II: 24 min from Bortle 6
- Hercules Cluster with the Vaonis Vespera II: 7 min from Bortle 6
- Hercules Cluster with the Vaonis Vespera Pro: 16 min from Bortle 6
- Hercules Cluster with the Vaonis Vespera 3: 7 min from Bortle 6
- Hercules Cluster with the Vaonis Vespera Pro 2: 15 min from Bortle 6
- Hercules Cluster with the Unistellar Odyssey: 28 min from Bortle 6
- Hercules Cluster with the Celestron Origin: 5 min from Bortle 6
- Hercules Cluster with the Celestron Origin Mark II: 5 min from Bortle 6
All telescopes for the Hercules Cluster · All targets for the eQuinox 2